Treatments for stage 1 breast cancer

The following are treatment options for stage 1 ductal carcinoma and lobular carcinoma. Stage 1 is divided into stage 1A and stage 1B, which doctors consider early stage breast cancer. Your healthcare team will suggest treatments based on your needs and work with you to develop a treatment plan.

Surgery

Surgery is the main treatment for stage 1 breast cancer.

Breast-conserving surgery is offered if doctors can remove all of the tumour along with a margin of healthy tissue around it and there will still be enough tissue for the breast to look as natural as possible after surgery.

Mastectomy is offered if there is cancer in more than one area of the breast or in the tissue removed along with the tumour during breast-conserving surgery (called positive surgical margins). It is also offered if a tumour isn’t found in the breast but a very small amount of cancer is in the lymph nodes (stage 1B). A woman may also choose to have a mastectomy.

Sentinel lymph node biopsy (SLNB) is often offered for early stage breast cancer. If the results of the SLNB show that there is cancer in the sentinel lymph node, or if the sentinel node can’t be found, a woman may be offered a choice between radiation therapy or an axillary lymph node dissection (ALND).

Radiation therapy

External beam radiation therapy is offered after breast-conserving surgery for stage 1 breast cancer. All of the breast and the lymph nodes under the arm and near the collarbone are treated. An extra dose, or boost, of radiation may be given to the area where the tumour was removed.

Radiation therapy is not usually offered after mastectomy for stage 1 breast cancer. It may be given if there was a positive sentinel node found during SLND.

When chemotherapy is a part of the treatment plan, radiation therapy will be given after chemotherapy is finished.

Hormonal therapy

Tamoxifen (Nolvadex, Tamofen) is the most commonly used anti-estrogen hormonal therapy drug offered to both premenopausal and post-menopausal women.

Aromatase inhibitors are given only to post-menopausal women. They may be offered after tamoxifen therapy or instead of tamoxifen if you can’t take or would prefer not to take tamoxifen. The most common aromatase inhibitors used are:

Hormonal therapy for premenopausal women

You will take tamoxifen for 5 years, then your healthcare team will check if you have reached menopause:

If you are still premenopausal, you can continue to take tamoxifen for up to 10 years in total.

If you have reached menopause, your healthcare team may offer you the option to continue tamoxifen for up to 10 years in total or to switch to an aromatase inhibitor for up to 5 years (for up to a total of 10 years of hormonal therapy).

Older premenopausal women may be offered ovarian ablation or suppression, along with tamoxifen or an aromatase inhibitor, for up to 10 years.

Targeted therapy

Trastuzumab (Herceptin) is added to chemotherapy for stage 1 breast cancer that is HER2 positive and has a high risk for recurrence. It is usually given for up to a year after chemotherapy for breast cancer has finished.

Clinical trials

Many clinical trials in Canada are open to women with breast cancer. Clinical trials look at new ways to prevent, find and treat cancer. Find out more about clinical trials.

premenopause

The time before menopause.

Premenopausal means referring to or having to do with the time before menopause.

post-menopause

The time after menopause.

Post-menopausal means referring to or having to do with the time after menopause.

aromatase inhibitor

A drug that stops the production or blocks the actions of the enzyme aromatase, which in turn lowers the level of estradiol (a female hormone) in the body.